This invention relates to enclosures for steel conversion apparatus.
The pneumatic type of steel conversion apparatus generally includes an open-topped vessel into which oxygen is injected by a lance or tuyers extending through the vessel's refractory lining. When submerged tuyerses are used, a hydrocarbon shielding fluid, such as light oil, natural gas or propane, may be injected in surrounding relation to the oxygen for prolonging tuyere life. As a result of the reactions which occur during pneumatic steel making processes, pollutant gases and particulate material are discharged from the open upper end of the vessel. In order to prevent the discharge of these pollutants, such vessels are often provided with a smoke hood coupled to a gas cleaning system and having a skirt movable into and out of close proximity to the charge receiving opening in the upper end of the vessel. During a normal process cycle, the skirt is elevated to permit the vessel to be pivoted for charging, sampling, pouring and deslagging. Also the skirt is normally separated from the vessel during the beginning and end portions of the cycle. Accordingly, an enclosure may be provided around the vessel for preventing discharge of pollutants during such charging operations. An access door in one side of the enclosure may be opened and closed for periodic charging. Prior art enclosures were provided with an opening which permitted the movable skirt to reciprocate. This was not wholly satisfactory, however, because pollutants tended to discharge through this opening when the skirt was elevated.